The Monster group $M$ is the largest sporadic simple group. It is also the group of automorphisms of $196, 884$-dimensional Fischer-Norton-Griess algebra $V_M$. In 2009, A. A. Ivanov offered an axiomatic approach to studying the structure of $V_M$ by introducing the notions of Majorana algebra and Majorana representation. Later, the theory developed, and Majorana representations of several groups were constructed. Our talk is dedicated to the existence of standard Majorana representations of 3-transposition groups for the Fischer list.

A Kirkman Triple System (KTS) is called $m$-pyramidal if there exists a subgroup $G$ of its automorphism group that fixes $m$ points of the KTS and acts regularly on the other points. Such a group $G$ admits a unique conjugacy class $C$ of involutions (elements of order 2) and $|C|=m$. We call groups with this property $m$-pyramidal. We prove that, if $m$ is an odd prime power $p^k$, then every $m$-pyramidal group is solvable if and only if either $m=9$ or $k$ is odd. We also determine the sizes of the vertex sets of the $m$-pyramidal KTS when $m$ is a prime number.

Seguindo a ideia no artigo de Hu e Vercruysse [1], introduzimos morfismos parciais em uma categoria arbitrária $\textbf{C}$, de modo que ações parciais de um monoide $M$ em um conjunto $X$ correspondem a certas funções de $M$ para o conjunto de classes de isomorfismo de morfismos parciais de $X$ para $X$ na categoria de conjuntos.

In this talk we present some properties of generalized torsion elements in groups. Moreover, we try connect this "new'' concept with the usual concept of torsion in some standard class of groups (e.g., nilpotent, FC-groups). This presentation is mainly based in the following papers [1,2,3,4]. This is joint work with C. Schneider and D. Silveira.   
      

References

[1] R. Bastos, C. Schneider and D. Silveira. Generalized torsion elements in groups.  To appear in Arch. Math. Basel (2023), arXiv:2302.09589.  

Let us consider the action of the general linear group $\mathrm{GL}_n(\mathbb{C})$ on the direct product $\mathcal{M}_n^d$
of $d$ copies of $\mathcal{M}_n$ by simultaneous conjugation sending $(X_1,\ldots, X_d)$ to $(gX_1g^{-1},\ldots,gX_dg^{-1})$
for any $g\in \mathrm{GL}_n(\mathbb{C})$ . This induces an action of $\mathrm{GL}_n(\mathbb{C})$ on the algebra $\mathbb{C}[\mathcal{M}_n^d]$ of polynomial
functions on $\mathcal{M}_n^d$. The algebra of invariants under this action, $\mathbb{C}[\mathcal{M}_n^d]^{\mathrm{GL}_n}$, is an important

The Grassmann convexity conjecture by B. Shapiro and M. Shapiro admits
several equivalent formulations.
One of them gives a conjectural formula for the maximal total number
of real zeros of the consecutive Wronskians of an arbitrary
fundamental solution to a disconjugate linear ordinary differential
equation with real time.
Another formulation is in terms of convex curves in the nilpotent
lower triangular group.
There is a very elementary formulation in terms of lists of vectors in $\mathbb{R}^k$.

Vamos considerar a conectividade de coberturas por dominós usando movimentos locais.
Em particular, nos concentraremos no movimento conhecido como flip, no qual dois dominós adjacentes são removidos e recolocados em outra posição.
Em dimensão 2, é possível ligar quaisquer duas coberturas de uma região simplesmente conexa por meio de uma sequência de flips.
No entanto, em dimensão 3, existem regiões simplesmente conexas onde flips não são suficientes para conectar qualquer par de coberturas.

A ring (associative with identity) is called a fine ring if every nonzero element in it is the sum of a unit and a nilpotent element.  G. Cǎlugǎreanu and T.Y. Lam initiated the study of fine rings in  "Fine rings: a new class of simple rings.", J. Algebra Appl. (2016). In this talk, we review known results and discuss some new developments of this study.

We aim to study Morita theory for tensor triangulated categories. For two finite tensor categories having no projective simple objects, we prove that their stable equivalence induced by an exact k-linear monoidal functor can be lifted to a tensor equivalence under some certain conditions.

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Yuying Xu is currently a PhD student at Nanjing University and University of Stuttgart.

(This is joint work with J. Delgado and M. Roy) For two subgroups of a group, $H_1, H_2\leq G$, we can look at the eight possibilities for the finite/non-finite generability of $H_1$, $H_2$, and $H_1\cap H_2$. For example, all eight are possible in a free non-abelian group except one of them, expressing the well-known fact that free groups are Howson: intersection of two finitely generated subgroups is again finitely generated.